Frequency Measurement Procedure - Furuno FS-1575 Service Manual

4) Connect a 50 ohm dummy load to the [TX OUT] of the TX board, and then connect
a frequency counter to each end of the dummy load.
TX OUT

2. Frequency measurement procedure

SSB frequency measurement procedure)
1. Select [MENU] -> 9.SERVICE -> 3.RT SETUP -> 4.TX PWR (FREQ), and then
press the [ENTER] knob. The TX POWER (FREQ) window will appear.
2. Select on "TX MODE," and then press the [ENTER] knob. The "TX MODE"
popup window will appear. Select on "SSB," and then press the [ENTER] knob.
3. Select on "TX FREQ," and then press the [ENTER] knob. The "TX FREQ" popup
window will appear. For example, enter 4100.0 kHz, and then press the [ENTER]
knob.
4. Select on "TX POWER," and then press the [ENTER] knob. The "TX POWER"
popup window will appear. Select on "LOW," and then press the [ENTER] knob.
5. Select on "TX TONE," and then press the [ENTER] knob. The "TX TONE" popup
window will appear, select on "SSB" -> "1500 Hz," and then press the [ENTER]
knob.
Reference)
When selecting [MENU] -> 7.AUDIO -> 2.OFF HOOK SP -> "SP ON,"
1500 Hz tone signal will be outputted from the speaker. This allows for making
TONE frequency measurement.
6. Press the PTT on the handset. Transmission will be initiated. Then, make
transmission frequency measurement. The frequency deviation is within ±10 Hz.
SSB output frequency = Set TX frequency + 1500 Hz (Tone)
Reference) Besides the above procedure, the frequency measurement can be made
following the procedure described in "5.6 TONE TEST" on page 5-32.
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It is strictly prohibited to reproduce the document in whole or in part without prior written permission of FURUNO.
5.4 Frequency Measurement and Adjustment
50-ohm Dummy
Frequency Counter
5-27